Compilare: user.cpp: In function ‘int main()’: user.cpp:13:20: warning: converting to non-pointer type ‘char’ from NULL [-Wconversion-null] t[strlen(t)-1]=NULL; ^ user.cpp:17:20: warning: converting to non-pointer type ‘char’ from NULL [-Wconversion-null] s[strlen(s)-1]=NULL; ^ user.cpp:21:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<=strlen(s)-strlen(t)+1;i++) ^ user.cpp:23:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<=strlen(t)-1 && ok==1;j++) ^ user.cpp:9:12: warning: unused variable ‘x’ [-Wunused-variable] char x,s[20000001],t[20000001]; ^ user.cpp:12:24: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets(t,2000001,f); ^ user.cpp:16:25: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets(s,20000001,f); ^ user.cpp:37:6: warning: ‘nr1’ may be used uninitialized in this function [-Wmaybe-uninitialized] for(i=1;i<=nr1;i++) ^